Adjustable Grinding Platform and Mounting Assembly

ABSTRACT

A grinding platform with an axis of rotation that is on the plane of the abrasive when used with belt grinders and on the plane that is vertical and tangent to the curvature of the abrasive when used with wheel grinders; such grinder having an angle gauge and possibly a vernier scale that allow for accurate determination of the angle of the tool rest in relation to the grinding surface. The grinding platform can also be continuously adjusted horizontally to compensate for wheel wear.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/478,342, filed on Apr. 22, 2012, which is incorporated by reference herein in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to adjustable grinding platforms or tool rests used in conjunction with grinding wheels and abrasive belts.

2. Description of Related Art

Grinding platforms, also called work rests, are commonly used in conjunction with belt sanders, belt grinders, and grinding wheels for the mechanized abrasive removal, or grinding, of materials. Just about any material can be grinded, such as: metal, wood, or plastic. Grinders and belt sanders are often used for the shaping and sharpening of metal tools, such as woodworking tools. This is typically accomplished by using a vertical grinding wheel mounted on a bench or a stand, but can also be accomplished by using abrasive belts which are part of a belt grinder or sander. The following discussion will discuss grinding platforms for sharpening woodworking tools; however, this invention is not limited to use in the context of sharpening tools.

Sharpening woodworking tools is typically accomplished by resting the tool on the grinder platform such that the longitudinal axis of the tool is parallel to the plane created by the top of the platform surface. The tool is then pressed toward the abrasive surface by hand. Employing this handheld method requires a tool platform that adequately supports the workpiece as well as having the platform set to the correct angle and position to obtain the desired angle of the sharpened edge of the workpiece.

It is fairly common for grinding platforms to incorporate a fixture to assist with making angular measurements between the grinding platform and the abrasive surface. A problem common to such fixtures is that they measure the angle of the platform, not the angle of the point of impact of the workpiece placed upon the grinding platform with the grinding wheel, which is where the true angle of the edge of the workpiece is created. This problem increases with grinding wheels because they vary in diameter over time due to wear and attrition.

There are several methods commonly used for determining the variable angular relationship between a grinding surface and a grinding platform or tool rest and workpiece. One method involves a trial and error process of grinding the workpiece and measuring the resulting angle of the sharpened workpiece. Another method involves several prepared blocks of wood, called jigs, with the desired angle cut on one of the corners. This method is quick, but requires many jigs to accommodate many angles. Another method involves placing a protractor on the grinding platform and flat along the side of the grinding wheel, or belt, such that the center point of the angle of the protractor is on the plane of abrasion; however, this method requires adjustment of the protractor in addition to adjustment of the grinding platform. Additionally, the size of the protractor may introduce error in the measurement of the angle created on the tip of the workpiece by failing to measure the angle where the workpiece actually comes into contact with the arc length of the perimeter of the grinding wheel. Yet another method involves using a digital angle gauge which provides fast angular measurement, but does not allow for nearly simultaneous setting of the platform angle. Additionally, such digital angle gauges require a power source and are subject to loss of calibration through use.

SUMMARY

According to embodiments of the present invention, the present invention may comprise: a platform and a mounting assembly; said platform having an axis of rotation capable of being on the plane of a surface when the grinding platform is adjacent to a planar surface and on the plane that is vertical and tangent to the curvature of a surface when adjacent to a curved surface; and the mounting assembly of which has a platform pivoting centerline coincident with the plane that is defined by the top surface of the platform and is capable of continuous or indexed horizontal and vertical movement of a platform.

The platform or mounting assembly may also comprise a fixed angle gauge capable of accurately determining the angle of the platform relative to a planar or curved surface, such angle gauge may incorporate a vernier scale. Embodiments of the platform and mounting assembly may also have removable platform supports, interchangeable platforms of various dimensions, and be capable of an angular adjustment of one hundred and sixty five degrees or more.

A method for setting up an embodiment of the grinder platform and mounting assembly comprising; providing adequate vertical clearance between the mounting assembly and an abrasive surface; aligning the longitudinal centerline of the mounting assembly with the center of the face of the abrasive surface; and allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface.

A method for setting up an embodiment of the grinder platform and mounting assembly for a planar or convex surface comprising; establishing the vertical position of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to the convex surface; establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to the convex abrasive surface; and adjusting the angle of the platform to the desired angle.

A method for manufacturing an embodiment of the grinder platform and mounting assembly comprising primarily machining extrusions.

While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

OBJECTS AND ADVANTAGES

None of the particular objects or advantages that follow must be entirely satisfied as they are non-exclusive alternatives and at least one of the following objects is met; accordingly, several objects and advantages of the present invention are:

(a) to provide a platform having an axis of rotation capable of being on the plane of a surface when the grinding platform is adjacent to a planar surface and on the plane that is vertical and tangent to the curvature of a surface when adjacent to a curved surface;

(b) to provide a mounting assembly that has platform pivoting centerline coincident with the plane that is defined by the top surface of the platform;

(c) to provide a mounting assembly which is capable of continuous or indexed horizontal and vertical movement of a platform;

(d) to provide a work rest with a fixed angle gauge capable of accurately determining the angle of the platform relative to a planar or curved surface;

(e) to provide a work rest with a fixed angle gauge incorporating a vernier scale;

(f) to provide a work rest capable of an angular adjustment of one hundred and sixty five degrees or more;

(g) to provide a work rest with interchangeable platforms of various dimensions;

(h) to provide a work rest with removable platform supports;

(i) to provide a method for manufacturing an embodiment of the grinder platform and mounting assembly that comprises of primarily machining extrusions;

(j) to provide a method for setting up an embodiment of the grinder platform and mounting assembly comprising; providing adequate vertical clearance between the mounting assembly and an abrasive surface; aligning the longitudinal centerline of the mounting assembly with the center of the face of the abrasive surface; and allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface;

(k) to provide a method for setting up an embodiment of the grinder platform and mounting assembly for a planar or convex surface comprising; establishing the vertical position of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to the convex surface; establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to the convex abrasive surface; and adjusting the angle of the platform to the desired angle;

(l) these and other objects and advantages of the invention will be apparent from the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figures

FIG. 1 (on sheet 1) illustrates a side view of a complete grinding platform assembly according to embodiments of the present invention.

FIG. 1A (on Sheet 1) illustrates a front view of a complete grinding platform assembly according to embodiments of the present invention.

FIG. 1B (on Sheet 1) illustrates an isometric perspective view of a complete grinding platform assembly as seen from the front according to embodiments of the present invention.

FIG. 1C (on Sheet 1) illustrates an isometric perspective view of a complete grinding platform assembly as seen from the back according to embodiments of the present invention.

FIG. 2 (on Sheet 2) illustrates an isometric perspective exploded view of a movable portion of a grinding platform assembly as seen from the front according to embodiments of the present invention.

FIG. 2A (on Sheet 2) illustrates an exploded front view of a movable portion of a grinding platform assembly according to embodiments of the present invention.

FIG. 3A (on Sheet 3) illustrates a left side view and a front view of a left side grinding platform assembly upright 2 according to embodiments of the present invention.

FIG. 3B (on Sheet 3) illustrates a right side view and a front view of a right side grinding platform assembly upright 3 according to embodiments of the present invention.

FIG. 3C (on Sheet 3) illustrates an isometric perspective view of platform uprights 2 and 3, showing that they are mirror images of one another according to embodiments of the present invention.

FIG. 3D (on Sheet 3) illustrates an Isometric Perspective View of platform upright workpieces after cutoff and before machining according to embodiments of the present invention.

FIG. 3E (on Sheet 3) illustrates an Isometric Perspective View of platform upright extrusions before any machining according to embodiments of the present invention.

FIG. 3F (on Sheet 3) illustrates isomeric perspective close-up views of the tops of two grinding platform assembly uprights, 2 and 3, showing an angle scale according to embodiments of the present invention.

FIG. 4 (on Sheet 4) illustrates an end view of a sliding baseplate 4 extrusion according to embodiments of the present invention.

FIG. 4A (on Sheet 4) illustrates an isometric perspective view of a partially assembled fixed baseplate assembly, incorporating a fixed baseplate 5, a sliding baseplate locking screw 9, a baseplate clamping plate 12, and a baseplate clamping plate retaining screw 13 according to embodiments of the present invention.

FIG. 4B (on Sheet 4) illustrates an end view and an isometric perspective view of a machined sliding baseplate 4 according to embodiments of the present invention.

FIG. 4C (on Sheet 4) illustrates an end view of a fixed baseplate assembly according to embodiments of the present invention.

FIG. 4D (on Sheet 4) illustrates an end view of a complete baseplate assembly according to embodiments of the present invention.

FIG. 4E (on Sheet 4) illustrates an end view of a fixed baseplate extrusion 5 according to embodiments of the present invention.

FIG. 4F (on Sheet 4) illustrates side and isometric perspective views of sliding mechanism clamping components 9, 12, and 13 according to embodiments of the present invention.

FIG. 5 (on Sheet 5) illustrates an isometric perspective transverse cross section view of the underside of a standard platform 1 according to embodiments of the present invention.

FIG. 5A (on Sheet 5) illustrates an isometric perspective view of the top side of a standard platform 1 according to embodiments of the present invention.

FIG. 5B (on Sheet 5) illustrates an isometric perspective view of the underside of a standard platform 1 according to embodiments of the present invention.

FIG. 5C (on Sheet 5) illustrates an isometric perspective view of an optional slotted platform 1 i according to embodiments of the present invention.

FIG. 5D (on Sheet 5) illustrates a top view of an optional small platform 1 h according to embodiments of the present invention.

FIG. 5E (on Sheet 5) illustrates a top view of an optional slotted platform 1 i according to embodiments of the present invention.

FIG. 5F (on Sheet 5) illustrates a top view of an optional large platform lk according to embodiments of the present invention.

FIG. 5G (on Sheet 5) illustrates a top view of a standard platform 1 according to embodiments of the present invention.

FIG. 6 (on Sheet 6) illustrates a side view of a theoretical vertical belt grinder with grinding platform assemblies installed adjacent to a flat grinding belt surface 14 created by a flat backing surface and adjacent to a cylindrical convex grinding surface 15 according to embodiments of the present invention.

FIG. 7 (on Sheet 7) illustrates a front isometric perspective view of a theoretical standard grinding platform assembly in conjunction with the flat backing surface portion of a belt grinder according to embodiments of the present invention.

FIG. 7A (on Sheet 7) illustrates a side view of a grinding platform assembly in conjunction with the flat backing surface portion of a belt grinder according to embodiments of the present invention.

FIG. 8 (on Sheet 8) illustrates a side view of a grinding platform assembly installed adjacent to a cylindrical convex grinding surface 15 created by a common sized wheel on a belt grinder according to embodiments of the present invention.

FIG. 8A (on Sheet 8) illustrates a front isometric perspective view of a grinding platform assembly installed adjacent to a cylindrical convex grinding surface 15 created by a common sized wheel on a belt grinder according to embodiments of the present invention.

FIG. 9 (on Sheet 9) illustrates a front isometric perspective view of a grinding platform assembly as mounted in conjunction with a horizontal-shaft-mounted peripheral wheel grinder according to embodiments of the present invention.

FIG. 9A (on Sheet 9) illustrates a close-up left side view of a grinding platform assembly as mounted in conjunction with a horizontal-shaft-mounted peripheral wheel grinder according to embodiments of the present invention.

FIG. 9B (on Sheet 9) illustrates a close-up rear isometric perspective view of a left side grinding platform assembly upright 2 according to embodiments of the present invention.

FIG. 10 (on Sheet 10) illustrates a side view of a grinding platform as mounted in conjunction with a horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on the platform according to embodiments of the present invention.

FIG. 10A (on Sheet 10) illustrates a close-up sectioned side view of a grinding platform 1 as mounted in conjunction with a wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11 (on Sheet 11) illustrates a close-up sectioned side view example of a grinding platform 1 as mounted in conjunction with a ten-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11A (on Sheet 11) illustrates a close-up example of a sectioned side view of a grinding platform 1 as mounted in conjunction with a nine-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11B (on Sheet 11) illustrates a close-up sectioned side view example of a grinding platform 1 as mounted in conjunction with a theoretical eight-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11C (on Sheet 11) illustrates a side view example of a grinding platform 1 as mounted in conjunction with a theoretical ten-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11D (on Sheet 11) illustrates a side view example of a grinding platform 1 as mounted in conjunction with a theoretical nine-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 11E (on Sheet 11) illustrates a side view example of a grinding platform 1 as mounted in conjunction with an theoretical eight-inch diameter horizontal-shaft-mounted peripheral wheel grinder which has a workpiece of thickness 19 mounted on a platform according to embodiments of the present invention.

FIG. 12 (on Sheet 12) illustrates a close-up rear isometric perspective view of the top of a platform assembly, showing the details in a platform 1 for the clearance cutout for an abrasive width as well as a scalloped platform wheel clearance 1 b for an abrasive curvature of a convex abrasive surface. The details of a platform angle indicator plate 7, an angle indicator plate edge 7 a, and an angle indicator vernier scale 7 b are also shown according to embodiments of the present invention.

FIG. 13 (on Sheet 13) illustrates a close-up sectioned left side view of a grinding platform 1 as mounted in conjunction with a horizontal-shaft-mounted peripheral wheel grinder and showing alternate platform angles as well as illustrating the extent of the range of one embodiment of the platform angle positions according to embodiments of the present invention.

FIG. 13A (on Sheet 13) illustrates a close-up right side view of a grinding platform 1 as mounted in conjunction with a horizontal-shaft-mounted peripheral wheel grinder as well as illustrating the extent of the range of one embodiment of the platform angle positions according to embodiments of the present invention.

REFERENCES

-   -   1 Platform     -   1 a Platform Pin     -   1 b Platform Wheel Clearance     -   1 c Platform Pivot Range—typical     -   1 d Platform Pivot Range—special     -   1 e Platform Pivoting Centerline     -   1 f Workpiece Thickness Midline     -   1 g Workpiece Thickness Maximum     -   1 h Short Half-Round Platform Design     -   1 i Slotted Platform Design     -   1 j Slot Detail in the Slotted Platform     -   1 k Long Platform Design     -   1L Platform Assembly Lateral Movement     -   2 Left Upright     -   2 a Left Upright Angle Indicator Scale     -   3 Right Upright     -   3 a Right Upright Angle Indicator Scale     -   4 Sliding Baseplate     -   4 a Vertical Travel of Uprights and Platform     -   5 Fixed Baseplate     -   5 a Fixed Baseplate Mounting Screws     -   6 Platform Pivot Locking Screw     -   7 Angle Indicator Plate     -   7 a Angle Indicator Plate Edge     -   7 b Angle Indicator Vernier Scale     -   8 Table Pin Bushing     -   9 Sliding Baseplate Locking Screws     -   10 Threaded Connector     -   11 Upright Locking Screws     -   12 Baseplate Clamping Plate     -   13 Baseplate Clamping Plate Retaining Screw     -   14 Flat Abrasive Surface     -   15 Convex Abrasive Surface     -   16 Bottom Mounting Base     -   17 Convex Abrasive Surface Maximum Outside Diameter     -   18 Convex Abrasive Surface Minimum Outside Diameter     -   19 Workpiece Thickness

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. However, the illustrated embodiments are merely exemplary and many additional embodiments of this invention are possible. It is understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the illustrated devices, and such further application of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates.

Unless otherwise indicated, the drawings are intended to be read (e.g., arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

FIG. 1 illustrates a side view of an embodiment of the adjustable grinding platform and mounting assembly while FIGS. 1A, 1B, and 1C illustrate the end, isometric perspective (from the front), and isometric perspective (from the rear) views respectively. In these stand-alone views, the entire assembly is not yet attached to a platform nor is it adjacent to an abrasive source. Some pertinent design details are apparent in these views. A fixed baseplate 5 contains a sliding baseplate 4. The details of a fixed baseplate 5 can be seen in an isometric perspective view shown in FIG. 4A and an end view shown in FIG. 4E. This component begins as, but is not limited to, an aluminum extrusion which can be subsequently drilled to accommodate fixed baseplate mounting screws 5 a and sliding baseplate locking screws 9, examples of which are shown in FIGS. 4A, 4C, 4D, 4F, 6, 7, 7A, 8, 8A, 9, and 10.

The details for the sliding baseplate 4 can be seen in FIG. 4 and FIG. 4B. This component begins as, but is not limited to, an aluminum extrusion which can be subsequently drilled to accommodate a threaded connector 10 as shown in FIGS. 4B and 4D.

Uprights 2 and 3 are attached to the sliding baseplate 4 as illustrated in FIGS. 1, 1A, 1B, and 1C. The uprights begin as, but are not limited to, aluminum extrusions as shown in FIG. 3E which can subsequently be cut into lengths as shown in FIG. 3D. These uprights, 2 and 3, can then be machined in alternate ways; resulting in two components that are mirror images of one another: the left upright 2 and the right upright 3, as illustrated in the isometric perspective drawings in FIG. 3C. Traditional front and side views of the uprights, 2 and 3, are shown in FIGS. 3A and 3B.

A platform 1 is then affixed between the two uprights, 2 and 3, as illustrated in FIGS. 1, 1A, 1B, and 1C. The platform begins as, but is not limited to, a stainless steel plate which is subsequently processed and machined in such a way as to obtain a shape; such as, but not limited to, that shown in FIG. 2A. The platform 1 can also be of alternate shapes so as to accommodate different sizes and styles of workpieces. These alternatives can be, but are not limited to, those shown in FIGS. 5C, 5D, 5E, and 5F.

One means for preparing the assembly of platform 1 with the uprights 2 and 3 is through the addition and attachment of platform pins 1 a, as shown in FIGS. 2 and 2A. These pins can be internally threaded and attached to the platform 1 by, but not limited to, brazing. The remainder of the attachment of the platform 1 to the uprights 2 and 3 can include an angle indicator 7, two table pin bushings 8, and two platform pivot locking screws 6, all of which are shown in FIGS. 2 and 2A. Other means for attaching platform 1 to uprights 1 and 2 may also be used. One design characteristic of the configuration of this platform subassembly is that the platform pivoting centerline 1 e is coincident with the plane that is defined by the top surface of the platform 1.

With the uprights, 2 and 3, and platform 1 assembled together; this assembly can be attached to a sliding baseplate 4. One means for attaching the platform subassembly and uprights, 2 and 3, to the sliding baseplate 4 is by placing upright locking screws 11 through slots in the lower portion of the uprights, 2 and 3; such upright locking screws 11 can then be threaded into oppositely threaded ends of the threaded connector 10 which can pass through sliding baseplate 4. This assembly then makes up the movable portion of the grinding platform that slides laterally in relation to a fixed baseplate 5.

The movable assembly can then be fitted into a fixed baseplate 5 by inserting the sliding baseplate 4 into an opening as shown in FIG. 4D. The position of the sliding baseplate 4 can be secured by a clamping mechanism as shown in FIG. 4A and FIG. 4F; other means for temporarily securing the two pieces of metal together may also be used. The baseplate clamps shown are composed of a baseplate clamping plate 12, a baseplate clamping plate retaining screw 13, and sliding baseplate locking screws 9. These last three components are assembled through holes in the sides of fixed baseplate 5. The clamping mechanism can be operated by turning the sliding baseplate locking screws 9, causing the baseplate clamping plate 12 to be pressed against the sliding baseplate 4, effectively clamping the sliding baseplate 4 at a secure lateral position inside the fixed baseplate 5 as shown in FIG. 4D.

Use of the entire adjustable grinding platform and the platform mounting assembly can be accomplished by mounting it to a bottom mounting base 16, the bottom mounting base 16 may be of a variety of shapes and materials, examples of which are shown in FIGS. 6, 7, 7A, 8, 8A, 9, 10, 11C, 11D, and 11E. For most applications, the bottom mounting base 16 will also serve as an operating base for the abrasive tool, such as belt grinders, or pedestal straight wheel grinders; examples of which are shown in FIGS. 6, 7, 7A, 8, 8A, 9, 10, 11C, 11D, and 11E. Attachment of the adjustable grinding platform and platform mounting assembly to the base 16 may be obtained through a number of attachment mechanisms, such as screws, pins, clamps or any other commonly used means of attachment. One such means of attachment is through the use of mounting screws 5 a that are installed through machined holes in flanges of the fixed baseplate 5 and into a mounting base 16, as shown in FIGS. 6, 7, 7A, 8, 8A, 9, 10, 11C, 11D, and 11E.

Care should be taken during the installation of the adjustable grinding platform and the platform mounting assembly so that several alignment requirements are assured. First, there should be adequate vertical clearance between the bottom mounting base 16 and the abrasive belt, or wheel, to allow for the installation of a fixed baseplate 5. Second, the centerline of the adjustable grinding platform and the platform mounting assembly; that is, the longitudinal centerline of the sliding baseplate 4; should be coincident with approximate center of the face width of the abrasive belt or wheel. Third, this same longitudinal centerline of the sliding baseplate 4 should be at a 90 degree horizontal angle to the axis of rotation of the wheel of the abrasive unit regardless of whether that wheel is part of a belt grinder as illustrated in FIGS. 6, 7, 7A, 8, 8A, or is part of a bench or pedestal straight wheel grinder as illustrated in FIGS. 8, 8A, 9, 10, 11C, 11D, and 11E. And fourth, the bottom mounting base 16 should be placed longitudinally along this same longitudinal centerline such that there is always available lateral longitudinal adjustment 1L for the sliding baseplate 4 regardless of the size, or change of size, of the abrasive wheel.

This available lateral longitudinal adjustment 1L is particularly necessary when the adjustable grinding platform and platform mounting assembly is used in conjunction with the straight vitrified wheel of a bench or pedestal grinder; as illustrated in FIGS. 11, 11A, 11B, 11C, 11D, and 11E; which illustrate the lateral longitudinal adjustments 1L required as the wheel begins service life as a 10-inch diameter as shown in FIG. 11C and wears away to 9-inch diameter as shown in FIG. 11D, then to an 8-inch diameter as shown in FIG. 11E. Setup of the adjustable grinding platform and the platform mounting assembly by the operator should take into account service life of the grinding wheel and the size range that will be seen over that service life. For example, initially setting up for a wheel diameter of 8 inches and providing for travel adjustments as required down to a wheel diameter of 5 inches.

FIG. 6 is a side view of an adjustable grinding platform and platform mounting assembly installed at both ends of a generic belt grinder. For this grinding device the lateral position of the abrasive surface does not change position during the time of use of the abrasive. The left hand side of FIG. 6 shows the installation on the portion of the abrasive surface that is in a vertical plane. FIG. 7 shows an isometric perspective view of this installation, and FIG. 7A is a larger sized side view of this arrangement.

Setup of the platform as shown in FIGS. 6, 7, and 7A, can be a three step process. First, the vertical position of the platform is established. Since the area of the contact surface with the abrasive incorporates an insignificant vertical length, the selected height is only a matter of personal preference. Once selected, the upright locking screws 11; or other means of securing the platform; can be tightened and thus the platform height is both established and secured. The second step is positioning the platform pivoting centerline 1 e at a horizontal position that places the platform pivoting centerline 1 e in the plane of the flat abrasive surface 14. This is done by loosening the sliding baseplate locking screws 9, which allows the sliding baseplate 4 lateral movement 1L within the fixed baseplate 5. Once the platform pivoting centerline 1 e intersects with the flat abrasive surface 14 and they are mutually coplanar, the sliding baseplate locking screws 9 can be tightened and the platform's lateral position is both established and secure. The third, and final, step is adjustment of the angle of the platform 1. This is done by loosening the platform pivot locking screws 6, or other means of securing the platform angle, adjusting the platform to the desired angle; then tightening the platform pivot locking screws 6.

A possible range of platform angles for this embodiment can be seen in FIG. 7A. A typical platform pivoting range of use 1 c is shown, as is a special platform pivoting range of use 1 d. A total range of pivoting movement can be, but is not limited to, 165 degrees: from straight up to 15 degrees from straight down. All of these angles can be set without any other adjustments being required for either platform height or lateral horizontal position.

The right hand side of FIG. 6 shows an adjustable grinding platform and platform mounting assembly on a portion of an abrasive surface that is a cylinder. FIG. 8A shows an isometric perspective view of this configuration of an adjustable grinding platform and platform mounting assembly, and FIG. 8 is a larger sized side view of this configuration. Setup of the adjustable grinding platform and the platform mounting assembly in this configuration can also be a three step process. This setup is the same for either the convex surface of a belt grinder wheel or the straight vitrified wheel of a bench or pedestal grinder.

FIG. 10 illustrates the various parameters involved in the setup for a convex surface. First, the vertical position 4 a of the platform 1 is established. Since the area of the contact surface with the abrasive (abrasive belt 15 in FIG. 8, straight grinding wheel 17 in FIG. 10) is convex, the selected height is not a matter of personal preference. To set the proper height, the platform 1 should first be positioned at 90 degrees, or exactly horizontal as seen in FIG. 8. With the platform 1 secured in this position, the thickness of the workpiece 19 needs to be measured. For this discussion, we will use an example as follows—grinding of a wood turning tool that is 0.20 inches thick to an included wedge angle of 40 degrees. The optimum position of the platform 1 is at a height such that the workpiece thickness midline 1 f is coincident with the horizontal line created by a vertical plane that is tangent to the convex abrasive surface (abrasive belt 15 in FIG. 8, straight grinding wheel 17 in FIG. 10). For this particular example, this would require that the platform pivoting centerline 1 e, and thus the platform top surface, be positioned 0.100 inches below this vertical tangent contact line. To obtain this height in a quick and simple manner, and at an acceptable degree of accuracy and repeatability for all common sharpening applications, the height of the platform pivoting centerline 1 e should be adjusted such that the engagement of the detents (engaging indentations) of uprights 2 and 3 with the detents of the sliding baseplate 4 place the height of the platform pivoting centerline 1 e the equivalent of one detent below the horizontal line created by a vertical plane that is tangent to the convex abrasive surface. In practice this is very quick and easy to do by placing a try square on the platform and, from the side, sighting along the front of the platform 1 with the naked eye. Once the height has been selected, the upright locking screws 11 can be tightened and thus the platform height is established and secure.

The second step involved in setup for a convex surface is positioning the platform pivoting centerline 1 e at a horizontal position that places 1 e in the vertical plane that is tangent to the convex abrasive surface (abrasive belt 15 in FIG. 8, straight grinding wheel 17 in FIG. 10). This adjustment is done by loosening the sliding baseplate locking screws 9; or other means of attachment; which allows the sliding baseplate 4 to move within the fixed baseplate 5, allowing lateral adjustment 1L. Here again, employing a try square makes this a quick and easy procedure by simply sighting from the side of the platform. Once the platform pivoting centerline 1 e and the vertical tangent plane of the convex abrasive surface (abrasive belt 15 in FIG. 8, straight grinding wheel 17 in FIG. 10) are aligned, the sliding baseplate locking screws 9; or other means of attachment; are tightened and thus the platform lateral position is established and secure. The third, and final, setup step is to adjust the angle of the platform 1. This adjustment is accomplished by loosening the platform pivot locking screws 6, or other means of attachment; adjusting the platform to the desired angle; 40 degrees in this example; and then tightening the platform pivot locking screws 6.

The grinding angle (40 degrees in this example) is easily determined. The angle is read directly from the scales 2 a and 3 a that are printed on the top ends of the uprights 2 and 3, as shown most clearly in the close-up isometric perspective view illustrated in FIG. 12. Simply determine the intersection of the angle indicator plate edge 7 a of the angle indicator plate 7 with the scales 2 a or 3 a to determine the angle to the nearest five degrees. Then use the angle indicator plate vernier scale 7 b to determine the angle to the nearest single degree. Alternate angle gauges can be displayed on alternative embodiments of this invention in alternate locations as the axis of the pivot of the grinder platform is on the abrasive surface for planar abrasive surfaces or on the vertical line tangent to the radius of a curved abrasive surface the angle gauge will still read a true angular relationship between the platform and the abrasive surface.

FIG. 13 illustrates a close-up sectioned side view of a grinding platform 1 as mounted in conjunction with a straight wheel grinder showing alternate platform angles. FIG. 13A illustrates a close-up side view of a grinding platform 1 as mounted in conjunction with a straight wheel grinder showing alternate platform angles. The range of these angles are shown as 1 c and 1 d, with 1 c being the range commonly used for sharpening such things as wood turning tools and 1 d representing the range of angles used less frequently. The grinding wheel 17 is shown, in this embodiment, when at a possible maximum initial diameter and also as 18, the smaller diameter that results after some substantial use and consequent abrasive wheel attrition. Note that the platform 1 height has been established using the method described above such that the workpiece thickness midline 1 f is coincident with the tangent line of a vertical plane and grinding wheel diameter 17 and the platform pivoting centerline 1 e lies in that same vertical tangent plane.

With a proper setup arrangement, two important aspects of the platform become more apparent. First, the platform angle can be changed without any other adjustments being required. This would apply if the wedge angle of the sharpened tool was to be changed or if additional tools of a different type but of the same thickness were to be ground during the same sharpening session. The second aspect of importance is that the attrition of the abrasive and the subsequent reduction of the grinding wheel diameter does not require a major revision to the setup. The entire sliding baseplate subassembly is simply moved towards the wheel as indicated by 1L until the platform pivoting centerline 1 e again becomes coplanar with the vertical plane that is now tangent to the new wheel size. This latter aspect is particularly advantageous to the user who has many tools of approximately the same thickness. In a matter of seconds the sliding baseplate subassembly can be changed to accommodate the sharpening of any tool in this thickness range.

Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.

CONCLUSION

This adjustable grinding platform and mounting assembly invention provides quick, easy, and accurate platform adjustments using a scale that defines the platform's angular axis of adjustment which is on the surface of a planar abrasive or the vertical plane tangent to the radius of a curved surface; continuous compensation for abrasive wheel diameter attrition; advantageous incremental or continuous height adjustment; exchangeable platforms; and stability that can be used with a variety of mechanical abrasive processes. While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. Accordingly, the scope of this invention should be determined not by the embodiments, but by the applied claims and their legal equivalents. 

1. A work rest, the work rest comprising: a platform having a top surface, wherein the platform is capable of having an axis of rotation on a plane of a planar surface when the platform is adjacent to the planar surface or on a plane that is vertical and tangent to a curvature of a surface when the platform is adjacent to the curved surface; a mounting assembly, wherein the mounting assembly is capable of having a platform pivoting centerline on a plane of the top surface of the platform and is capable of horizontal or vertical movement of a platform; wherein the platform is fixed or removably attached to the mounting assembly.
 2. The work rest of claim 1, wherein the platform or mounting assembly has a fixed angle gauge capable of accurately determining the angle of the top surface of the platform relative to a plane of a planar surface when the platform is adjacent to the planar surface or to a plane that is vertical and tangent to a curvature of a surface when the platform is adjacent to the curved surface.
 3. The work rest of claim 2, wherein said angle gauge incorporates a vernier scale.
 4. The work rest of claim 1, wherein the platform comprises interchangeable platforms of various dimensions.
 5. The work rest of claim 1, wherein the platform is capable of an angular adjustment of one hundred and sixty five degrees or more.
 6. The work rest of claim 1, wherein the mounting assembly has removable upright platform supports.
 7. The work rest of claim 1, wherein the work rest is aluminum.
 8. The work rest of claim 1, wherein the platform has a bottom surface with slots thereon.
 9. The work rest of claim 1, wherein the platform has a bottom surface platform wheel indenture.
 10. A method for using a work rest having a tilting platform with a top surface attached to a mounting assembly capable of horizontal extension adjacent to a planar or curved surface comprising: providing adequate vertical clearance between the mounting assembly and the surface; aligning the longitudinal centerline of the mounting assembly perpendicular to the center of the face of the surface; and allowing for the horizontal extension of the mounting assembly to be toward the abrasive surface.
 11. The method of claim 10, further comprising: establishing the vertical position of the top surface of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to a curved surface.
 12. The method of claim 11, further comprising: establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to a curved surface.
 13. The method of claim 12, further comprising: adjusting the angle of the platform to the desired angle.
 14. The method of claim 10, further comprising: establishing the horizontal position of the platform such that the tilting axis of the platform is in the vertical plane that is tangent to a curved surface.
 15. The method of claim 14, further comprising: establishing the vertical position of the top surface of the platform such that a workpiece's thickness midline is at the same height as a horizontal line created by a vertical plane that is tangent to a curved surface.
 16. The method of claim 15, further comprising: adjusting the angle of the platform to the desired angle. 